title: Meta-analysis of air pollution exposure association with allergic sensitization in European birth cohorts.
abstract: BACKGROUND
  Evidence on the long-term effects of air pollution exposure on childhood allergy is limited.
  
  
  OBJECTIVE
  We investigated the association between air pollution exposure and allergic sensitization to common allergens in children followed prospectively during the first 10 years of life.
  
  
  METHODS
  Five European birth cohorts participating in the European Study of Cohorts for Air Pollution Effects project were included: BAMSE (Sweden), LISAplus and GINIplus (Germany), MAAS (Great Britain), and PIAMA (The Netherlands). Land-use regression models were applied to assess the individual residential outdoor levels of particulate matter with an aerodynamic diameter of less than 2.5 μm (PM2.5), the mass concentration of particles between 2.5 and 10 μm in size, and levels of particulate matter with an aerodynamic diameter of less than 10 μm (PM10), as well as measurement of the blackness of PM2.5 filters and nitrogen dioxide and nitrogen oxide levels. Blood samples drawn at 4 to 6 years of age, 8 to 10 years of age, or both from more than 6500 children were analyzed for allergen-specific serum IgE against common allergens. Associations were assessed by using multiple logistic regression and subsequent meta-analysis.
  
  
  RESULTS
  The prevalence of sensitization to any common allergen within the 5 cohorts ranged between 24.1% and 40.4% at the age of 4 to 6 years and between 34.8% and 47.9% at the age of 8 to 10 years. Overall, air pollution exposure was not associated with sensitization to any common allergen, with odds ratios ranging from 0.94 (95% CI, 0.63-1.40) for a 1 × 10(-5) ∙ m(-1) increase in measurement of the blackness of PM2.5 filters to 1.26 (95% CI, 0.90-1.77) for a 5 μg/m(3) increase in PM2.5 exposure at birth address. Further analyses did not provide consistent evidence for a modification of the air pollution effects by sex, family history of atopy, or moving status.
  
  
  CONCLUSIONS
  No clear associations between air pollution exposure and development of allergic sensitization in children up to 10 years of age were revealed.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Electronic address: olena.gruzieva@ki.se.
authors.forename: Olena
authors.initials: O
authors.lastname: Gruzieva
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Gehring
authors.affiliation: Sanquin Research, Amsterdam, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Aalberse
authors.affiliation: Centre for Epidemiology, Institute of Population Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Raymond
authors.initials: R
authors.lastname: Agius
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Beelen
authors.affiliation: ZAUM-Centre for Allergy and Environment, Technical University (TUM)/Helmholtz Center Munich, Munich, Germany.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Behrendt
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
authors.forename: Tom
authors.initials: T
authors.lastname: Bellander
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology I, Neuherberg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Birk
authors.affiliation: Department of Pediatrics, Erasmus University Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands.
authors.forename: Johan C
authors.initials: JC
authors.lastname: de Jongste
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology I, Neuherberg, Germany.
authors.forename: Elaine
authors.initials: E
authors.lastname: Fuertes
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology I, Neuherberg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Heinrich
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Gerard
authors.initials: G
authors.lastname: Hoek
authors.affiliation: IUF Leibniz Research Institute for Environmental Medicine at the University of Düsseldorf, Düsseldorff, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Klümper
authors.affiliation: Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Gerard
authors.initials: G
authors.lastname: Koppelman
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Michal
authors.initials: M
authors.lastname: Korek
authors.affiliation: IUF Leibniz Research Institute for Environmental Medicine at the University of Düsseldorf, Düsseldorff, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Krämer
authors.affiliation: School of Environment and Development (Geography), University of Manchester, Manchester, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Lindley
authors.affiliation: Centre for Epidemiology, Institute of Population Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Anna
authors.initials: A
authors.lastname: Mölter
authors.affiliation: Institute of Inflammation and Repair, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, United Kingdom.
authors.forename: Angela
authors.initials: A
authors.lastname: Simpson
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology I, Neuherberg, Germany.
authors.forename: Marie
authors.initials: M
authors.lastname: Standl
authors.affiliation: Department of Medicine, Clinical Immunology and Allergy Unit, Karolinska Institutet and University Hospital, Stockholm, Sweden.
authors.forename: Marianne
authors.initials: M
authors.lastname: van Hage
authors.affiliation: Marien-Hospital Wesel, Research Institute, Department of Pediatrics, Wesel, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: von Berg
authors.affiliation: Centre for Prevention and Health Services Research, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
authors.forename: Alet
authors.initials: A
authors.lastname: Wijga
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Pershagen
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009569:Nitric Oxide / Q000032:analysis; D011446:Prospective Studies
chemical_list: D009569:Nitric Oxide; D007073:Immunoglobulin E
keywords: Air pollution; European Study of Cohorts for Air Pollution Effects; IgE; children; cohort; meta-analysis; sensitization